Switch depending on speed

Hi
Anyone that can point me in the right direction?

I want to have a switch that is on/off depending of speed.
I know speedometer can use hal pulse to show speed, but is
there a way to control a switch.
Im building a Etrike TTW. only want it to be tiltable in speed
over 15km/h kinda. So need an on/off signal.
Have 2 Qs-motor 6Kw with 2 Kellycontroller kls-7245h

Kind regards
Stefan

I'm sure there are several ways to do it. These days most guys would use an Arduino. I'm an older, more analog guy, so I would use a frequency to voltage converter and a comparator.

If you search eBay for "speed sensor switch", you'll see a bunch of little boards that look like they will do what you want. You can pull 5v from the controller throttle to power it. Unfortunately, there isn't enough information in the advertisement to know if this board will work for your application, but for $1, there isn't a lot of risk. I think it is the right circuit, but may not have the range you want.

https://www.ebay.com/sch/i.html?_sop=15&LH_BIN=1&_from=R40&_sacat=0&_nkw=speed+sensor+switch&_pgn=2&_skc=50&rt=nc

Hi
Thanks for quick reply!
Thank you for advice, not sure i understand how those works.
Now i have something to start searching on
Think i need it to be adjustable to find right speed.

Without hall pulse i was thinking of having switch on throttle power 0-5v, but that would not work.
If you release throttle in speed while free rolling, the switch will be activated in wrong speed.

Any more suggestions?

Stefan

I think he's suggesting using the 5V throttle hall sensor supply line to power that device. It's always sending 5V to the throttle sensor, doesn't vary with throttle position. There's a separate wire that does that (1-4V output or whatever). I'm not sure if that unit is adjustable either.

I'd go Arduino if I were you. It will give you all the flexibility you need. Ask on the Arduino forums https://forum.arduino.cc/ there's a good chance someone has already done it.

Right, I was suggesting getting a fixed 5v to power the little board from the throttle. You could use any 5v source.

I'm not sure how those boards work, but they have an adjustment pot to set the speed where it kicks in. I don't know what the speed range is and whether you could use the hall signals from the motor. There may be a fixed resistor or capacitor on the board that could change the range of adjustment.

Efu said:

Hi
Anyone that can point me in the right direction?

I want to have a switch that is on/off depending of speed.
I know speedometer can use hal pulse to show speed, but is
there a way to control a switch.
Im building a Etrike TTW. only want it to be tiltable in speed
over 15km/h kinda. So need an on/off signal.
Have 2 Qs-motor 6Kw with 2 Kellycontroller kls-7245h

Click to expand...

Go with Arduino!!
You need to read the hall sensors signal to get the motor speed, very easy to do!! The motor controllers does this way.
What if your motor don't have hall sensors?? then the kelly controller is using internally an algorithm (angle estimator) that calc the motor speed but you will not have access to that information. Maybe you can simple use a speed sensor (can be bought here: https://bmsbattery.com/) and then use the Arduino to measure the speed sensor output.

Good luck in your project and please post some pictures after!!